We generated and compared Drosophila models of RET fusions CCDC6-RET and NCOA4-RET. Both RET fusions directed cells to migrate, delaminate, and undergo EMT, and both resulted in lethality when ...broadly expressed. In all phenotypes examined, NCOA4-RET was more severe than CCDC6-RET, mirroring their effects on patients. A functional screen against the Drosophila kinome and a library of cancer drugs found that CCDC6-RET and NCOA4-RET acted through different signaling networks and displayed distinct drug sensitivities. Combining data from the kinome and drug screens identified the WEE1 inhibitor AZD1775 plus the multi-kinase inhibitor sorafenib as a synergistic drug combination that is specific for NCOA4-RET. Our work emphasizes the importance of identifying and tailoring a patient’s treatment to their specific RET fusion isoform and identifies a multi-targeted therapy that may prove effective against tumors containing the NCOA4-RET fusion.
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•Drosophila RET fusion cancer models have multiple transformation phenotypes•Similar to patients, NCOA4-RET presents with more severe phenotypes than CCDC6-RET•CCDC6-RET and NCOA4-RET activate distinct pathways and have different drug sensitivity•A drug treatment, sorafenib plus AZD1775 (MK-1775), was effective for NCOA4-RET animals
Levinson and Cagan examine two Drosophila RET-fusion models. They find that the N terminus contributes to the overall function of fusion proteins, including their response to therapeutics. Genetic and chemical genetic screens identify a drug combination of sorafenib plus AZD1775 as being effective against the NCOA4-RET fusion.
The risk of specific cancers increases in patients with metabolic dysfunction, including obesity and diabetes. Here, we use Drosophila as a model to explore the effects of diet on tumor progression. ...Feeding Drosophila a diet high in carbohydrates was previously demonstrated to direct metabolic dysfunction, including hyperglycemia, hyperinsulinemia, and insulin resistance. We demonstrate that high dietary sugar also converts Ras/Src-transformed tissue from localized growths to aggressive tumors with emergent metastases. Whereas most tissues displayed insulin resistance, Ras/Src tumors retained insulin pathway sensitivity, increased the ability to import glucose, and resisted apoptosis. High dietary sugar increased canonical Wingless/Wnt pathway activity, which upregulated insulin receptor gene expression to promote insulin sensitivity. The result is a feed-forward circuit that amplified diet-mediated malignant phenotypes within Ras/Src-transformed tumors. By targeting multiple steps in this circuit with rationally applied drug combinations, we demonstrate the potential of combinatorial drug intervention to treat diet-enhanced malignant tumors.
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•High dietary sugar enhances Ras/Src-mediated transformation in Drosophila•Ras/Src-activated tumors evade diet-mediated insulin resistance•Insulin resistance evasion is due to Wingless-mediated insulin receptor upregulation•Rational targeting of multiple pathways can reduce diet-enhanced tumors
A study in Drosophila identifies how Ras/Src-activated cancer cells drive Wnt-dependent expression of the insulin receptor, even under conditions of whole-organism insulin resistance, thereby unraveling a possible link between metabolic syndrome and cancer.
We have developed a Drosophila lung cancer model by targeting Ras1G12V—alone or in combination with PTEN knockdown—to the Drosophila tracheal system. This led to overproliferation of tracheal tissue, ...formation of tumor-like growths, and animal lethality. Screening a library of FDA-approved drugs identified several that improved overall animal survival. We explored two hits: the MEK inhibitor trametinib and the HMG-CoA reductase inhibitor fluvastatin. Oral administration of these drugs inhibited Ras and PI3K pathway activity, respectively; in addition, fluvastatin inhibited protein prenylation downstream of HMG-CoA reductase to promote survival. Combining drugs led to synergistic suppression of tumor formation and rescue lethality; similar synergy was observed in human A549 lung adenocarcinoma cells. Notably, fluvastatin acted both within transformed cells and also to reduce whole-body trametinib toxicity in flies. Our work supports and provides further context for exploring the potential of combining statins with MAPK inhibitors such as trametinib to improve overall therapeutic index.
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•A Drosophila Ras-Pten lung cancer model was established•Altering cancer genes in the trachea led to growth and migration defects•Screening identified trametinib plus fluvastatin as a candidate therapeutic cocktail•Trametinib/fluvastatin showed synergistic efficacy in human lung cancer cell line
Levine and Cagan describe an oncogenic Ras-driven lung cancer model in Drosophila that is used in a whole-animal drug screen of over 1,000 FDA-approved compounds. Two hits, the MEK inhibitor trametinib and the statin fluvastatin, synergized to rescue oncogenic phenotypes and lethality.
The complexity of cancer has led to recent interest in polypharmacological approaches for developing kinase-inhibitor drugs; however, optimal kinase-inhibition profiles remain difficult to predict. ...Using a Ret-kinase-driven Drosophila model of multiple endocrine neoplasia type 2 and kinome-wide drug profiling, here we identify that AD57 rescues oncogenic Ret-induced lethality, whereas related Ret inhibitors imparted reduced efficacy and enhanced toxicity. Drosophila genetics and compound profiling defined three pathways accounting for the mechanistic basis of efficacy and dose-limiting toxicity. Inhibition of Ret plus Raf, Src and S6K was required for optimal animal survival, whereas inhibition of the 'anti-target' Tor led to toxicity owing to release of negative feedback. Rational synthetic tailoring to eliminate Tor binding afforded AD80 and AD81, compounds featuring balanced pathway inhibition, improved efficacy and low toxicity in Drosophila and mammalian multiple endocrine neoplasia type 2 models. Combining kinase-focused chemistry, kinome-wide profiling and Drosophila genetics provides a powerful systems pharmacology approach towards developing compounds with a maximal therapeutic index.
Celotno besedilo
Dostopno za:
DOBA, IJS, IZUM, KILJ, KISLJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Modeling Cancer with Flies and Fish Cagan, Ross L.; Zon, Leonard I.; White, Richard M.
Developmental cell,
05/2019, Letnik:
49, Številka:
3
Journal Article
Recenzirano
Odprti dostop
Cancer has joined heart disease as the leading source of mortality in the US. In an era of organoids, patient-derived xenografts, and organs on a chip, model organisms continue to thrive with a ...combination of powerful genetic tools, rapid pace of discovery, and affordability. Model organisms enable the analysis of both the tumor and its associated microenvironment, aspects that are particularly relevant to our understanding of metastasis and drug resistance. In this Perspective, we explore some of the strengths of fruit flies and zebrafish for addressing fundamental cancer questions and how these two organisms can contribute to identifying promising therapeutic candidates.
In this Perspective, Cagan et al. discuss how powerful genetic tools, a rapid pace of discovery, and affordability contribute to the strength of flies and zebrafish as models for cancer research. They highlight studies addressing fundamental cancer questions and consider how these organisms can contribute to identifying promising therapeutic candidates.
Diabetic nephropathy is a major cause of end-stage kidney disease. Characterized by progressive microvascular disease, most efforts have focused on injury to the glomerular endothelium. Recent work ...has suggested a role for the podocyte, a highly specialized component of the glomerular filtration barrier. Here, we demonstrate that the Drosophila nephrocyte, a cell analogous to the mammalian podocyte, displays defects that phenocopy aspects of diabetic nephropathy in animals fed chronic high dietary sucrose. Through functional studies, we identify an OGT-Polycomb-Knot-Sns pathway that links dietary sucrose to loss of the Nephrin ortholog Sns. Reducing OGT through genetic or drug means is sufficient to rescue loss of Sns, leading to overall extension of lifespan. We demonstrate upregulation of the Knot ortholog EBF2 in glomeruli of human diabetic nephropathy patients and a mouse ob/ob diabetes model. Furthermore, we demonstrate rescue of Nephrin expression and cell viability in ebf2−/− primary podocytes cultured in high glucose.
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•Diabetic nephropathy is a growing health problem worldwide•High dietary sugar led to loss of proper renal (nephrocyte) function in Drosophila•An OGT-Polycomb-Knot-Nephrin pathway mediates nephrocyte dysfunction•The Knot ortholog EBF2 mediates aspects of podocyte dysfunction in mice and humans
Diabetes-related kidney failure is a major source of morbidity and mortality worldwide. Na et al. provide evidence that glucose, OGT, Polycomb, EBF2, and Nephrin connect chronic high dietary sugar to loss of proper filtration in the Drosophila nephrocyte and mammalian podocyte.
Insulin-resistant, 'type 2' diabetes (T2D) results from a complex interplay between genes and environment. In particular, both caloric excess and obesity are strongly associated with T2D across many ...genetic backgrounds. To gain insights into how dietary excess affects insulin resistance, we studied the simple model organism Drosophila melanogaster. Larvae reared on a high-sugar diet were hyperglycemic, insulin resistant and accumulated fat--hallmarks of T2D--compared with those reared on control diets. Excess dietary sugars, but not fats or proteins, elicited insulin-resistant phenotypes. Expression of genes involved in lipogenesis, gluconeogenesis and β-oxidation was upregulated in high-sugar-fed larvae, as were FOXO targets, consistent with known mechanisms of insulin resistance in humans. These data establish a novel Drosophila model of diet-induced insulin resistance that bears strong similarity to the pathophysiology of T2D in humans.
Experimental models that capture the genetic complexity of human disease and allow mechanistic explorations of the underlying cell, tissue, and organ interactions are crucial to furthering our ...understanding of disease biology. Such models require combinatorial manipulations of multiple genes, often in more than one tissue at once. The ability to perform complex genetic manipulations in vivo is a key strength of Drosophila, where many tools for sophisticated and orthogonal genetic perturbations exist. However, combining the large number of transgenes required to establish more representative disease models and conducting mechanistic studies in these already complex genetic backgrounds is challenging. Here we present a design that pushes the limits of Drosophila genetics by allowing targeted combinatorial ectopic expression and knockdown of multiple genes from a single inducible transgene. The polycistronic transcript encoded by this transgene includes a synthetic short hairpin cluster cloned within an intron placed at the 5' end of the transcript, followed by two protein-coding sequences separated by the T2A sequence that mediates ribosome skipping. This technology is particularly useful for modeling genetically complex diseases like cancer, which typically involve concurrent activation of multiple oncogenes and loss of multiple tumor suppressors. Furthermore, consolidating multiple genetic perturbations into a single transgene further streamlines the ability to perform combinatorial genetic manipulations and makes it readily adaptable to a broad palette of transgenic systems. This flexible design for combinatorial genetic perturbations will also be a valuable tool for functionally exploring multigenic gene signatures identified from omics studies of human disease and creating humanized Drosophila models to characterize disease-associated variants in human genes. It can also be adapted for studying biological processes underlying normal tissue homeostasis and development that require simultaneous manipulation of many genes.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Throughout an individual's life, somatic cells acquire cancer-associated mutations. A fraction of these mutations trigger tumour formation, a phenomenon partly driven by the interplay of mutant and ...wild-type cell clones competing for dominance; conversely, other mutations function against tumour initiation. This mechanism of 'cell competition', can shift clone dynamics by evaluating the relative status of clonal populations, promoting 'winners' and eliminating 'losers'. This review examines the role of cell competition in the context of tumorigenesis, tumour progression and therapeutic intervention.
A key tool of cancer therapy has been targeted inhibition of oncogene-addicted pathways. However, efficacy has been limited by progressive emergence of resistance as transformed cells adapt. Here, we ...use
to dissect response to targeted therapies. Treatment with a range of kinase inhibitors led to hyperactivation of overall cellular networks, resulting in emergent resistance and expression of stem cell markers, including Sox2. Genetic and drug screens revealed that inhibitors of histone deacetylases, proteasome, and Hsp90 family of proteins restrained this network hyperactivation. These "network brake" cocktails, used as adjuncts, prevented emergent resistance and promoted cell death at subtherapeutic doses. Our results highlight a general response of cells, transformed and normal, to targeted therapies that leads to resistance and toxicity. Pairing targeted therapeutics with subtherapeutic doses of broad-acting "network brake" drugs may provide a means of extending therapeutic utility while reducing whole body toxicity.
These findings with a strong therapeutic potential provide an innovative approach of identifying effective combination treatments for cancer.
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